A loss-in-weight system is well known as a means for continuously discharging a fixed amount of material.
One example of such a loss-in-weight type continuous quantitative discharging device comprises a measuring means provided with weighing parts in combination having a material storage tank supported with a load cell under a material reserving chamber for reserving material and a quantitative discharging device provided under the material storage tank, a material supply means capable of supplying material to the weighing parts, and a control means which measures the material supplied from the material supply means and controls the supply of the supply means accompanied with the measurement and which controls the quantitative discharge of the quantitative discharging device (for example, see patent document 1).
This continuous quantitative discharging device measures two material storage tanks with a measuring part thereof. While the material in one of material storage tanks is quantitatively discharged, the material is supplied in the other material storage tank to be measured by the measuring part thereof. Further, when a quantitative discharge from one of material storage tanks is finished, the material in the other material storage tank is capable of being quantitatively discharged.
According to such a prior continuous quantitative discharging device, two material storage tanks are alternately operated to discharge the stored material by turns so as to continuously discharge a fixed amount of material.
Patent Document: JP-A-5-322633
Problems to be Solved in the Invention
However, according to such a prior continuous quantitative discharging device, two material storage tanks are required and a measuring part is provided respectively for each tank, thereby complicating the structure and enlarging the system.
Further, such a continuous quantitative discharging device is constructed such that two material storage tanks and the quantitative discharging device are synchronized. Therefore, when large amount of material is to be continuously discharged, it requires to wait until the material in either one of the material storage tanks becomes ready to quantitatively discharge material or it requires to reduce the discharge amount or to slow the discharge speed so as to make the material storage tank capable of discharging a fixed amount, thereby causing such a problem that materials are not continuously and smoothly discharged.
Still further, each load cell for measuring two material storage tanks is constructed so as to support the outside which is apart from the center of gravity of the material storage tank, so that accidental errors may be caused when the weight of the material storage tank is measured, thereby causing such a problem that stored material is not accurately weighed.
In addition, a blending system in which a plurality of continuous quantitative discharging devices are provided becomes complicated and enlarged.
Discharge outlet from each continuous quantitative discharging device is fixed in such a blending system, so that the material is not balanced depending on the discharge amount and the kinds of discharge material, thereby making the blend ratio of material uneven.
The object of the present invention is to solve those problems and the present invention provides a continuous quantitative discharging device using the device reduced in overall size and capable of accurately, smoothly, and continuously discharging a fixed amount of material and mixing the discharged material at a uniform mixing ratio and also a material blending system using the same.
Means to Solve the Problems
In order to achieve the above objects, a continuous quantitative discharging device as set forth in claim 1 comprises a material reserving chamber for storing material continuously supplied from a material supply means; a material storage tank having at a top a material inlet separated from the material reserving chamber for storing material fallen from the material reserving chamber and having at a lower part a discharge means capable of continuously and quantitatively discharging the stored material therefrom; a load cell type mass weighing part having a carrying arm secured to only the material storage tank in the material storage tank and supporting the carrying arm by a load cell provided on a support frame separated from the material storage tank in a non-contact state; and a controller for monitoring the weighed value of the load cell and controlling the discharge of material from the discharge means and/or the supply of material into the material storage tank.
The device is simple in structure, which is characterized by measuring by only one material storage tank, thereby enabling downsizing of the whole device.
Further the weight of storage material in the material storage tank and the weight of discharge material discharged by the discharge means have no relation, are not synchronized, so that the material can be continuously supplied in the material storage tank while continuously discharging material even when large amount of material is continuously discharged, thereby achieving smooth and continuous discharge and supply.
Further, the support frame is separately provided in a non-contact state such that it is free from the influence of the weight of material storage tank and the carrying arm is supported with the load cell provided on the support frame, so that the entire weight of material storage tank is applied to the load cell in the material storage tank.
According to such a structure, the load cell can be provided near the center of gravity point of the material storage tank, thereby measuring the weight of supplied material at high accuracy.
According to the continuous quantitative discharging device as set forth in claim 2, the carrying arm as set forth in claim 1 has a pointed roof at the upper part thereof.
According to the continuous quantitative discharging device, the carrying arm in the material storage tank has the pointed roof at the upper part thereof, so that the supplied material is prevented from being accumulated on the carrying arm while being dropped via the carrying arm, thereby enabling accurate measurement of weight of supplied material.
According to the continuous quantitative discharging device as set forth in claim 3, the carrying arm of claim 1 or 2 is a structure orthogonal to a vertical axis at a center of gravity of the material storage tank and the load cell is provided directly under the substantial center of the structure.
According to this continuous quantitative discharging device, the load cell is provided directly under the substantial center of the carrying arm, therefore the carrying arm can be made in a desirable shape such as a straight line or cross shape.
According to a material blending system as set forth in claim 4, a plurality of the continuous quantitative discharging devices as set forth in any one of claims 1, 2 or 3 are provided, and a mixing chamber is connected at a discharge outlet end of each discharge means so as to contain the material discharged from the discharge outlets and the materials are mixed and blended in the mixing chamber to be transported to a molding machine with a transporting means.
According to this material blending system, the whole system can be downsized and the materials discharged from each continuous quantitative discharging device are mixed and blended in the mixing chamber to be transported, thereby preventing the material unmixed and obtaining uniformly mixed material.
According to the material blending system as set forth in claim 5, the controller of claim 4 controls the revolution speed of discharge means in such a manner that materials are simultaneously discharged at a fixed discharging speed and are stopped discharging simultaneously and a blended material with a fixed blending ratio and of fixed amount is transported to the molding machine.
According to this blending system, the materials are simultaneously discharged until the materials discharged from a plurality of discharge means reach to a fixed amount and they are stopped discharging simultaneously, thereby uniformly discharging the blended material with a fixed blend ratio from beginning to end.
According to the material blending system as set forth in claim 6, the controller of claim 4 or 5 is designed to control discharge of a fixed amount of material without slowing down the revolution speed of discharge means while assuming dropping amount of material from the discharge outlet end depending on the revolution speed of discharge means when discharge is stopped.
According to this blending system, the dropping amount is assumed without slowing down the revolution speed of discharge means and a fixed amount of material is discharged, thereby reducing the discharging time and enhancing the efficiency.
According to the material blending system as set forth in claim 7, the controller of claim 6 memorizes the dropping amount of material discharged from the discharge means at several times, the total dropping amount is divided by the times to obtain a compensation value, and next discharge amount is automatically controlled.
According to this blending system, the controller automatically controls next discharge amount while adding the compensation value, thereby reducing the accidental errors of the set discharge amount and the actual discharge amount caused by the dropped amount of material and executing accurate material discharge as set in advance.
According to the material blending system as set forth in claim 8, the mixing chamber of any one of claims 4-7 includes a baffle plate into which the material discharged from each discharge outlet end runs while being dropped therein and the material is designed to be stored after such running.
According to this blending system, the dropping material is scattered by the baffle plate, its travel direction is misordered, and several kinds of materials are mixed while being scattered, thereby making the discharge material more uniformly.
According to the material blending system as set forth in claim 9, in the system of claim 8, an air hole is formed at the side wall of the mixing chamber behind the baffle board for taking a secondary air for pneumatic transportation.
According to this blending system, the air hole is formed at the side wall of mixing chamber behind the baffle plate, so that the baffle plate prevents the adverse current of material in the mixing chamber, thereby achieving smooth intake of secondary air.
According to the material blending system as set forth in claim 10, in the system of any one of claims 4-9, the transportation amount of transporting means is controlled by the controller.
According to this blending system, the controller controls the transporting amount of transportation means, thereby enabling automation from material supply to transportation.
According to the material blending system as set forth in claim 11, in the system of any one of claims 4-10, each controllers provided for the continuous quantitative discharging device is capable of exchanging information each other via communication lines.
According to this blending system, mutual information exchange is enabled among the plurality of continuous quantitative discharging devices, so that all continuous quantitative discharging devices can be managed and controlled by means of a specified controller.
Further, the Internet may be used other than a wired or wireless communication.
Effect of the Invention
The present invention has the following effects.
The continuous quantitative discharging device as set forth in claim 1 has such a simple structure of measuring only one material storage tank, thereby downsizing the whole device.
Further the weight of storage material in the material storage tank and the weight of discharge material discharged by the discharge means have no relation and are not synchronized, so that the material can be continuously supplied in the material storage tank while continuously discharging material even when large amount of material is continuously discharged, thereby achieving smooth and continuous discharge and supply.
Further, the support frame is provided in a non-contact state with the material storage tank such that it is free from the influence of the weight of material storage tank and the carrying arm is supported with the load cell provided on the support frame, so that the entire weight of material storage tank is applied to the load cell in the material storage tank.
According to such a structure, the load cell can be provided near the center of gravity of the material storage tank, thereby measuring the weight of supplied material at high accuracy.
According to the continuous quantitative discharging device as set forth in claim 2, the carrying arm in the material storage tank has the pointed roof at the upper part thereof, so that the supplied material is prevented from being accumulated on the carrying arm while being dropped via the carrying arm, thereby enabling accurate measurement of weight of supplied material.
According to the continuous quantitative discharging device as set forth in claim 3, the carrying arm is a structure orthogonal to a vertical axis at a center of gravity of the material storage tank the load cell is provided directly under the substantial center of the carrying arm, thereby forming the carrying arm in a desirable shape such as a straight line or cross.
According to the material blending system as set forth in claim 4, the entire system can be simplified to be downsized. Further, the materials discharged from each continuous quantitative discharging device are mixed and blended in the mixing chamber to be transported, thereby preventing the material unmixed and obtaining uniform mixed material.
According to the blending system as set forth in claim 5, the materials are simultaneously discharged until the materials discharged from a plurality of discharge means reach to a fixed amount and they are stopped discharging simultaneously, thereby uniformly discharging the blended material with a fixed blend ratio from beginning to end.
According to the blending system as set forth in claim 6, the dropping amount is assumed without slowing down the revolution speed of discharge means and a fixed amount of material is controlled to be discharged, thereby reducing the discharging time and enhancing the efficiency.
According to the blending system as set forth in claim 7, the controller automatically controls next discharge amount while adding the compensation value, thereby reducing the accidental errors of the set discharge amount and the actual discharge amount caused by the dropped amount of material and executing accurate material discharge as set in advance.
According to the blending system as set forth in claim 8, the dropping material is scattered by the baffle plate, its travel direction is misordered, and several kinds of materials are mixed while being scattered, thereby making the discharge material more uniformly.
According to the blending system as set forth in claim 9, the air hole is formed at the side wall of mixing chamber behind the baffle plate, so that the baffle plate prevents the adverse current of material in the mixing chamber, thereby achieving smooth intake of secondary air.
According to the blending system as set forth in claim 10, the controller controls the transporting amount of transportation means, thereby enabling automation from material supply to transportation.
According to the blending system as set forth in claim 11, mutual information exchange is enabled among the plurality of continuous quantitative discharging devices, so that all continuous quantitative discharging devices can be managed and controlled by means of a specified controller.